|This was a 32 year old patient whose bone marrow aspiration was done for a suspected diagnosis of a leukaemia. The aspirate yielded a scanty amount of pauciparticulate marrow. Blasts were seen. What was remarkable was the presence of many osteoclasts along a clot on the smear. One of the osteoclasts is seen here in low power. Note the size relative to the erythrocyte.
||The same osteoclast shown in the previous image unser 100X.
||Another osteoclast in the same smear. The multiple nuclei. Each nucleus is 1.5-2X adjoining erythrocytes. This gives an idea of the size of the cells.
||A megakaryocytic though a large cell like an osteoclast normally has a single multi-lobed nucleus
Osteoclast are multinucleate bone resorbing cells derived from the haemopoietic stem cell. An osteoclast is about 30-100μ in size and has multiple discrete oval nuclei. They have azurophilic granules. The megakaryocyte though a large cell, unlike an osteoclast, normally has a single multi-lobed nucleus. Osteoclasts are truly multinucleate. The azurophilic granules of osteoclasts are coarser.